Commit b7aa43b4 authored by Haiyang Zhang's avatar Haiyang Zhang Committed by Greg Kroah-Hartman

hv_netvsc: fix race that may miss tx queue wakeup

[ Upstream commit 93aa4792 ]

When the ring buffer is almost full due to RX completion messages, a
TX packet may reach the "low watermark" and cause the queue stopped.
If the TX completion arrives earlier than queue stopping, the wakeup
may be missed.

This patch moves the check for the last pending packet to cover both
EAGAIN and success cases, so the queue will be reliably waked up when
necessary.
Reported-and-tested-by: default avatarStephan Klein <stephan.klein@wegfinder.at>
Signed-off-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 7a154742
......@@ -875,12 +875,6 @@ static inline int netvsc_send_pkt(
} else if (ret == -EAGAIN) {
netif_tx_stop_queue(txq);
ndev_ctx->eth_stats.stop_queue++;
if (atomic_read(&nvchan->queue_sends) < 1 &&
!net_device->tx_disable) {
netif_tx_wake_queue(txq);
ndev_ctx->eth_stats.wake_queue++;
ret = -ENOSPC;
}
} else {
netdev_err(ndev,
"Unable to send packet pages %u len %u, ret %d\n",
......@@ -888,6 +882,15 @@ static inline int netvsc_send_pkt(
ret);
}
if (netif_tx_queue_stopped(txq) &&
atomic_read(&nvchan->queue_sends) < 1 &&
!net_device->tx_disable) {
netif_tx_wake_queue(txq);
ndev_ctx->eth_stats.wake_queue++;
if (ret == -EAGAIN)
ret = -ENOSPC;
}
return ret;
}
......
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